The present invention relates generally to automotive products and, more particularly, to an apparatus for adjusting the camber in the steerable front wheels of a vehicle having an independent front wheel suspension system.
In a conventional independent front wheel suspension system for an automotive vehicle, each wheel is mounted independently of the other. Each wheel is rotatably mounted on a wheel spindle which is fixedly bolted to an integrally formed ball joint and wheel knuckle assembly. The wheel knuckle portion of this assembly is in turn bolted to the lower end of an elongate, generally vertically extending shock strut. The upper end of the shock strut is attached to a body side panel, typically by a rubber insulated top mount assembly with attachment bolts. Due to the length and resiliency of the shock strut, the spindle and attached wheel are, to a small degree, displaceable in a direction perpendicular to the longitudinal axis of the shock strut and are also torsionally (twistably) displaceable about this axis if otherwise unrestrained. In order to restrain this movement and hold the wheel in a fixed orientation with respect to the vehicle steering assembly, a longitudinally extending restraining member, generally referred to as a tie rod, and a laterally extending restraining member, generally referred to as a control arm, is affixed at one end to the ball joint and wheel knuckle assembly and at an opposite end to the vehicle steering assembly. Due to manufacturing tolerances, etc. in the front wheel assemblies, the "camber" of a wheel in some cases needs adjustment. The "camber" of a wheel refers to the relative angle which the central plane of the wheel makes with a vertical axis extending perpendicular to the surface on which the vehicle is supported. Ordinarily the wheel knuckle in such a front wheel suspension system is fixedly bolted to a pair of laterally extending flanges affixed to a lower end of the strut assembly. In such an arrangement, camber adjustment can only be effected by using the relative "slop" provided between the bolt assembly and the associated bolt holes in the strut flanges and wheel knuckle. However, this "slop" provides very little camber adjustment. In one prior art cam adjustment assembly, an elliptical cam bolt assembly which engages factory-installed bosses on a strut flange is used to provide camber adjustment. However, most vehicles having the above described type of front wheel suspension system are not provided with such a cam adjustment assembly. It would be generally desirable to provide a cam adjustment assembly which could be easily retrofit on existing vehicles. However, providing bosses on a strut flange of the appropriate strength and tolerances for use with a cam bolt assembly is a very exacting and time-consuming operation which is beyond the skill of most automotive mechanics. Thus, until recently, there existed no convenient means for retrofitting a front wheel cam adjustment assembly on a vehicle having a front wheel suspension system of the type described above. Apparatus recently introduced for retrofitting a front wheel suspension system with a cam adjustment assembly is described in U.S. Pat. No. 4,706,987 issued Nov. 17, 1987, entitled CAMBER ADJUSTMENT DEVICE, of Craig R. Pettibone and Jimmy D. Berry; and in U.S. patent application Ser. No. 065,725 filed July 2, 1987, U.S. Pat. No. 4,733,884 entitled CAMBER ADJUSTMENT DEVICE, of Craig R. Pettibone and Jimmy D. Berry; both of which are hereby specifically incorporated by reference for all that is disclosed therein.
U.S. Pat. No. 4,706,987 discloses: a camber adjustment assembly for adjusting the camber of a wheel in a vehicle suspension system of the type ordinarily including a generally vertically extending strut assembly having an upper end attached to a vehicle frame assembly and having a pair of strut flanges positioned in parallel relationship with one another and projecting laterally outwardly from a lower end portion of the strut assembly; a wheel knuckle assembly mounted on the strut assembly and having a mounting portion positioned between the two strut flanges with a first hole therein adapted to closely, axially slidingly receive a first bolt therein which also passes through a first pair of coaxially aligned holes in the strut flanges in close axially sliding relationship and with a second hole therein adapted to closely, axially slidingly receive a second bolt which also passes through a second pair of coaxially aligned holes in the strut flanges in close axially sliding relationship, the first and second holes in the wheel knuckle mounting portion being vertically spaced apart, the first and second bolt holes in the wheel knuckle mounting portion and the first and second pair of holes in the strut flanges having axes positioned in substantially perpendicular relationship with the axis of rotation of a wheel supported on the wheel knuckle assembly, the camber adjustment assembly comprising: (a) parallel laterally extending slots provided in the pair of strut flanges by lateral extension of the first pair of holes therein; (b) a cam bolt assembly including a bolt and a cylindrical disc fixedly, eccentrically mounted at one end of the bolt, the cam bolt assembly having a central longitudinal axis for providing adjustable pivotal movement of the wheel knuckle about the axis of the second hole in the wheel knuckle mounting portion, the cam bolt being received in the parallel slots in the strut flanges and in the first hole in the wheel knuckle with the central longitudinal axis thereof positioned coaxially with the axis of the first hole in the wheel knuckle assembly and being adjustably laterally movable in the parallel slot in a first relatively loosened state of the cam bolt and being relatively fixed with respect to the parallel slot in a second relatively tightened state of the cam bolt; (c) a plate mounted on at least one of the strut flanges and adapted to coact with the strut flange and the cam bolt assembly for causing relative lateral displacement of the cam bolt assembly in the strut flange parallel slots during rotational movement of the cam bolt assembly about the cam bolt assembly central longitudinal axis in the first relatively loosened state; (d) whereby the camber of a wheel mounted on the wheel knuckle assembly is adjustable through rotation of the cam bolt assembly about the cam bolt assembly central longitudinal axis.
Patent application Ser. No. 065,725, U.S. Pat. No. 4,733,884 of Pettibone et al. discloses an insert member with an axially extending flange portion which is inserted into a plate to hold it in fixed relationship with an associated strut flange.